A new C29-sterol with a cyclopropane ring at C-25 and 26 from the Vietnamese marine sponge lanthella sp.

Abstract

One new C(29) sterol with a cyclopropane ring at C-25 and C-26, aragusteroketal B (1), and aragusterol B (2) were isolated from the Vietnamese marine sponge Ianthella sp. Their structures were elucidated by extensive spectroscopic analyses. Both 1 and 2 showed moderate cytotoxic activity against MCF-7, SK-Hep-1, and HeLa cell lines with IC(50) in the range of 12.8-27.8 microM.

Sterols from Thai Marine Sponge Petrosia (Strongylophora) sp. and Their Cytotoxicity

“…The location of the hydroxyl group at C-14 in 2 was assigned based on the HMBC correlations from H-15 and CH 3 -18 to C-14 (δ 87.2). Concerning the configuration of 14-OH in 2 , the 13 C chemical shifts of both C-9 and C-12 were significantly shifted upfield by ∆δC by approximately 6 ppm when compared with those reported for aragusterols I ( 6 ) [22] and B ( 7 ) [23] due to the γ-gauche effect [24]. These results established the hydroxyl group at C-14 as having an α-orientation.…”

“…The cyclopropane ring was assigned as possessing an E -geometry due to its NOESY correlation between H-25 and CH 3 -29. Moreover, the proton and carbon resonances of C-20–C-29 side chain of 1 were similar to those of aragusterols B ( 7 ) [23], I ( 6 ) [22], and xestokerol B ( 8 ) [21], indicating their identical relative configuration. In addition, the relative stereochemistry of the rings A–D (from C-1 to C-19) of 1 was deduced by the NOESY experiments as shown in Figure 3 and Figure S5.…”

“…Besides these eight new compounds, the eight known structures, aragusterol I ( 6 ) [22], aragusterol B ( 7 ) [23], xestokerol B ( 8 ) [21], petrosterol ( 9 ) [25], 7-oxopetrosterol ( 10 ) [4], xestokerol A ( 14 ) [21], aragusterol A ( 15 ) [20], and aragusterolketal ( 16 ) [19] were isolated and identified by NMR techniques and comparison of their spectral data ( 1 H and 13 C NMR and [α] D ) with literature values.…”

“…In a previous study, sterols with a cyclopropane ring were reported to possess cytotoxicity toward various cancer cell lines [19,20,23]. In our study, several compounds ( 1 – 4 , 6 – 8 , 10 , and 12 – 16 ) were evaluated for their cytotoxicity using a panel of human cancer cell lines, including MOLT-3 (acute lymphoblastic leukemia), HepG2 (hepatocarcinoma), A549 (human lung cancer), HuCCA-1 (human chlolangiocarcinoma), HeLa (cervical carcinoma), and MDA-MB-231 (hormone-independent breast cancer) as well as a normal cell line, MRC-5 (normal human embryonic lung fibroblasts).…”